【作者】 代俊萍；

【导师】 蔡民华； 裴真明；

【作者基本信息】 首都师范大学 ， 遗传学， 2005， 硕士

【摘要】 迄今为止,有关NO与细胞周期关系的研究在植物中报道很少。本实验以普通水稻（中作9052）为材料,硝普钠（sodium nitroprusside,SNP）为NO的供体,对NO与水稻细胞周期的关系进行了初步探讨。实验分为三个层次:1、用不同浓度SNP处理水稻初生根不同时间后观察其生长情况,结果显示,SNP对水稻初生根的生长存在抑制作用,而且这种抑制作用具有剂量和时间依赖性,当SNP浓度≥50μmol/L时,抑制作用表现已非常明显,到100μmol/L时几乎完全抑制其生长;从时间上来看,同一浓度SNP处理水稻根部三天时抑制作用表现最强,三天后逐步减弱。2、对SNP处理的水稻初生根根尖细胞进行细胞分裂相统计,结果表明:随SNP浓度的增大,细胞分裂指数呈下降趋势;而流式细胞术分析进一步确定NO对水稻细胞周期的阻抑作用发生在G₁→S期转化进程中,从而导致处于S/G₂/M期的细胞比例均下降。3、对经SNP处理与未处理的水稻细胞周期特异性表达基因cdc2Os-2、Histone H3、CDKB2;1及CycB2;2的表达水平进行实时定量PCR检测发现,NO对G₁→S期标志基因cdc2Os-2的表达具有抑制效应,说明NO确实阻抑了水稻细胞周期G₁→S期进程,这与细胞学结论吻合;此外,由于NO处理后的S/G₂/M期细胞比例均减少,所以Histone H3（S期）、CDKB2;1（S→G₂期）以及的CycB2;2（M期）等三个标志基因的表达也呈现减弱趋势。 本实验结果说明:NO对水稻细胞周期具有阻抑作用,这种阻抑发生在G₁→S转化进程中。更多还原

【Abstract】 Up until now, there are few reports of the relation between nitric oxide (NO) and cell cycle in plant. In this paper, sodium nitroprusside(SNP) was used as the donor of NO and was treated to the seeds of Oryza sativa LfZhong Zuo 9052) to primary investigate the relationship between NO and cell cycle of rice. The experiments were on the following three levels: l).the seeds were treated with different concentrations of SNP for different times. It was observed that SNP had inhibition on the growth of the primary roots and the inhibition was dose- and time-dependent, i.e, when SNP≥50μmol/L, the inhibition was very obvious, SNP=100μmol/L, the growth was fully inhibited; On the other hand, it was the most inhibited in the third day when the roots were treated in the same concentration of SNP and then weakened after three days.2).It was demonstrated that the cell cycle indexes were decreased as long as the concentrations of SNP were increased after collecting the cell division phase of the primary root-tip cells;it was indicated that the inhibition of NO on the cell cycle was in the transition of G1→S by flow cytometry analysis, so that the ratio of the cells in S/G2/M decreased.3).it was indicated, through the comparison of the expression level by realtime quantitative-PCR of the markers of cdc2Os-2,Histone H3,CDKB2;1 and CycB2;2 that were specialized in the cell cycle of Oryza sativa L,that NO had the inhibition to the marker of cdc2Os-2 that expresses from G1→ S.This result was consist with that in cytology. Since the ratio of the cellsin S/G2/M decreased after NO treatment,the expression of the other three markers--HistoneH3(S phase) CDKB2;1(S→G2 phase) and CycB2;2(M phase) were also decreased.Our results demonstrated that NO had the inhibition to cell cycle in Oryza sativa L,and the inhibition was in the transition of G1→S.更多还原